This invention relates to a process and apparatus for separating heavy metals such as gold, silver, platinum, copper, lead, etc., in their free state, from their surrounding ore. In some instances, the metal is present in mine tailings which heretofore had little, if any, commercial value because of the large recovery costs, and hence were abandoned.
In other instances, the metal is present in a natural occurring ore body, but not of sufficient size to permit economic recovery by conventional processes.
Various types of apparatus have in the past been employed to recover precious metals such as gold from tailings, raw ore, etc., using water washing techniques. One type of apparatus employed an inclined grooved wheel separator to which was fed a supply of ore which was then water washed. Gold particles sank to the bottom of the grooves and the rotation of the wheel caused the gold to be moved to a central orifice where it was recovered.
The basic problems with employing a single wheel or a plurality of wheels involved the use of feed augers for every wheel and the necessity for maintaining a uniform feed to each wheel. Once the beneficiated ore was removed from a wheel, it tended to dry out in a non-uniform fashion; this made it difficult to feed it uniformly to a succeeding wheel even with a mechanical device such as an auger.
Furthermore, more grooved-wheel separators produced a spectrum of ore grades each of which required separate treatment.
Consequently, many bodies of ore tailings still exist which contain gold but which could not be further economically refined with the available apparatus.
It is, therefore, an object of this invention to provide a process and apparatus therefor which is adapted to separate heavy metals including precious metals from their associated ore such as tailings, raw ore, sluice box cleanings, sand bodies such as found in rivers, in waste from sand plants, etc.
Other objects of this invention will become apparent from the description and single drawing to follow which shows a cross-section view of the apparatus of this invention in side elevation.